Latest Research News
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Low-temperature DeNOx catalyst for reducing ultrafine particle emission
7 times increased durability compared to conventional commercial catalysts. Empirical research conducted at an industrial field to check commercialization (Kumho Petrochemical Cogeneration Power Plant) <span style="background-color: rgb(255, 255, 255); color: rgb(51, 51, 51); font-family: 나눔고딕코딩, NanumGothicCoding, sans-serif; font-size: 14pt;" open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;"="">Recently, there has been growing demand for DeNOx catalysts that can treat nitrogen oxides (NOx) at low temperatures, to increase energy efficiency when processing flue gas in industrial combustion facilities. NOx are emitted during the combustion of fossil fuels and are the leading cause of ultrafine particles (UFPs) formed via chemical reactions in the atmosphere. <span style="background-color: rgb(255, 255, 255); color: rgb(51, 51, 51); font-family: 나눔고딕코딩, NanumGothicCoding, sans-serif; font-size: 14pt;" open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">However, existing catalysts have a problem of reduced durability due to the poisoning of the catalyst’s active sites because of the formation of ammonium sulfate, when sulfur in flue gas reacts with reducing agent ammonia at a low temperature (<250°C). To address this, studies have attempted to weaken the oxidation ability of sulfur oxide on the catalyst surface or delay the poisoning by limiting the reactivity of sulfur compounds; however, these solutions cannot increase the durability against sulfur. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">At the Extreme Materials Research Center, part of the Korea Institute of Science and Technology(KIST), a research team of Dr. Kwon, Dong Wook and Dr. Ha, Heon Phil announced the development of a high-durability low-temperature catalyst material for selective catalytic reduction (SCR); it can reduce NOx into water and nitrogen, which are harmless to the environment and the human body. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">The team successfully developed a composite vanadium oxide-based catalyst material that significantly limited the formation of poisonous ammonium sulfate by suppressing the adsorption reaction between the active sites and sulfur dioxide. A catalyst interface engineering technique was used in which molybdenum and antimony oxide were added to the vanadium-based catalyst. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">The developed vanadium oxide-based composite catalyst material has significantly increased catalytic life when exposed to sulfur dioxide at 220°C, with the time to reach 85% of the initial performance delayed by about seven times compared to that in the conventional catalyst. The developed catalyst is also energetically efficient due to increased low-temperature activity, which significantly lowers the burden of NOx treatment without reheating the exhaust gas. As a result, it is possible to reduce air pollutant treatment costs if the developed catalyst is applied to industrial sites in the future. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">After completing the laboratory-scale reactor experiment, the team installed a pilot demonstration facility at the Kumho Petrochemical’s Yeosu 2nd Energy Cogeneration Power Plant to test using actual flue gas. The KIST-Kumho Petrochemical team aims to establish plant facilities by 2022 after deriving an optimal operation plan by evaluating and verifying the driving variables of the demonstration facility for about ten months. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">Ko, Young Hoon, the head of R&BD center of Kumho Petrochemical (Vice-President), mentioned, “Reducing NOx, which accounts for most of the harmful substances in the exhaust gas of our Cogeneration Power Plant, is a critical issue for Kumho Petrochemical’s ESG management.” Then, he added, “We are successfully conducting empirical research by installing pilot equipment for power plants to secure preemptive reduction technology above the level of advanced countries, and we plan to conduct scale-up test of the technology in order to transform it to a high-durability low-temperature SCR catalytic commercial technology.” <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">Image <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); text-align: center;" open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"=""> <p style="text-align: center; box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51);" open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="" align="center">SCR PILOT DENOX REACTOR THROUGH ON-SITE EXHAUST GAS INJECTION.
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- WriterDr. Kwon, Dong Wook and Dr. Ha, Heon Phil
- 작성일2022.01.15
- Views739
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3D Digital Holograms on Smartphones?
Realized 3D digital holograms by developing a polarization image sensor with no additional polarization filters. Miniaturization of the entire holographic camera sensor module is possible with follow-up research 3D holograms, previously seen only in science fiction movies, may soon make their way into our daily lives. Until now, 3D holograms based on phase shifting holography method could be captured using a large, specialized camera with a polarizing filter. However, a Korean research group has just developed technology that can acquire holograms on mobile devices, such as smartphones. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"="">The Korea Institute of Science and Technology (KIST, Director Seok-jin Yoon) recently announced that a research team led by Dr. Min-Chul Park and Dr. Do Kyung Hwang of the Center for Opto-Electronic Materials and Devices, in collaboration with a research team led by Prof. Seongil Im of the Department of Physics at Yonsei University, was successful in developing a photodiode that detects the polarization of light in the near-infrared region without additional polarization filters and thus, the realization of a miniaturized holographic image sensor for 3D digital holograms, using the 2D semiconductor materials: rhenium diselenide and tungsten diselenide. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"="">Photodiodes, which convert light into current signals, are essential components within the pixels of image sensors in digital and smartphone cameras. Introducing the ability to sense the polarization of light to the image sensor of an ordinary camera provides a variety of new information, enabling the storage of 3D holograms. Previous polarization-sensing cameras have an additional polarization filter, several hundred micrometers in size, attached to an ultra-small optical diode image sensor, less than a micrometer in size. Thus, they could not be implemented into portable electronic devices because of their inability to be integrated and miniaturized. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"=""> <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"="">The research group developed a photodiode by stacking an n-type semiconductor, rhenium diselenide, which exhibits a difference in light absorption dependent on the linear polarization angle of light in the near-infrared (980 nm) region, and a p-type semiconductor, tungsten diselenide, which exhibits no difference in photo-response dependent on polarization, but enables superior performance. The device is excellent in the photodetection of various wavelengths from ultraviolet to near-infrared, even capable of selectively detecting the polarization characteristics of light in the near-infrared region. The research group utilized the device to create a digital holographic image sensor that records polarization characteristics to successfully capture holograms. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);="" line-height:="" 1.5;"=""> Dr. Hwang of KIST said, "Research on the downsizing and integration of individual elements is required to ultimately miniaturize holographic systems. The results of our research will lay the foundation for the future development of miniaturized holographic camera sensor modules." In addition, Dr. Park remarked, "The new sensor can further detect near-infrared light, as well as previously undetectable visible light, opening up new opportunities in various fields such as 3D night vision, self-driving, biotechnology, and near-infrared data acquisition for analyzing and restoring cultural assets." Image HOLOGRAM IMPLEMENTED WITH TWO-DIMENSIONAL SEMICONDUCTOR WSE2/RESE2, WHICH IS A POLARIZATION-SENSING PHOTODIODE, RESE2 ON THE FRONT AND WSE2 ON THE BACK ARE IMAGED IN THREE-DIMENSIONAL SPACE
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- WriterDr. Min-Chul Park and Dr. Do Kyung Hwang
- 작성일2022.01.05
- Views754
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Low concentrations of CO2→CO direct conversion technology
Flue gas level low-concentration carbon dioxide high-efficiency conversion made possible. Economically feasible electrochemical carbon dioxide conversion achieved A Korean research team has developed a technology that can produce carbon monoxide (CO), which has various applications in industry, by direct conversion of flue gas level low-concentration carbon dioxide (CO2). The Korean Institute of Science and Technology (KIST, President Seok-jin Yoon) announced that the research team of Dr. Da Hye Won and Dr. Ung Lee at Clean Energy Research Center and Professor Yun Jeong Hwang at Seoul National University (President Se-jung Oh) has developed a catalyst and a operating process that can produce CO with high efficiency using flue gas level low-concentration CO2. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">CO2 conversion to valuable chemicals is one of the most promising strategies for mitigating the global climate crisis and developing new processes for chemical production.However, these technologies require supply of high-concentration CO2 gas. This is because CO2 is chemically very stable, which makes it difficult to convert CO2 to other chemicals, and a high-concentration CO2 supply is needed to increase the reaction rate and the efficiency. Actual flue gas from industrial plants typically contains 10% CO2 along with other emissions such as nitrogen, oxygen, and nitrogen oxide; however, until now, it has not been possible to achieve enough efficiency from this low concentration of CO2. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">As a catalyst for electrochemical conversion of CO2 to CO, Ag is mainly used due to its high CO productivity. Commercial Ag nanopacticles produce 95% CO when high-concentration CO2 (99.99%) is used, while it produces 40% CO and 60% hydrogen when low-concentration (10%) CO2 is used. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">The research team at KIST has developed a nickel single-atom catalyst that can inhibit hydrogen production and increase CO production efficiency. Transition metals such as iron and nickel could not be used as CO2 conversion catalysts due to their lower reactivities than those of noble metals; however, the recent finding that using transition metals in single-atom structure can achieve high CO productivity motivated the team to develop the new catalyst. The team also developed an optimized operating techniques for advanced CO2 conversion system that can directly convert gas-fed low-concentration CO2 by using both experimental and computational simulation methods. <p style="box-sizing: border-box; margin-top: 5px; margin-bottom: 15px; color: rgb(51, 51, 51); font-family: " open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;="" background-color:="" rgb(255,="" 255,="" 255);"="">The developed nickel single-atom catalyst can produce 93% CO with low-concentration (10%) CO2, and it is also economically feasible by using non-precious materials composed of nickel and carbon compared to noble Ag catalyst. Dr. Da Hye Won at KIST said, “The developed catalyst and the operating techniques can be widely applied in electro-chemical conversion systems utilizing low-concentration carbon dioxide. And we are also in the process of development of various technologies to use the flue gas directly without any additional conditioning process to achieve the economic feasibility of electro-chemical carbon dioxide conversion technology.” Image DEVELOPED EXTRINSIC OPERATING CONDITIONS CONTROLLING THE WATER TRANSFER FROM THE ANOLYTE TO THE CATALYST LAYER AND IMPROVED CO SELECTIVITY AT LOW CO2 CONCENTRATIONS IN THE MEA ELECTROLYZER. <span open="" sans",="" "helvetica="" neue",="" helvetica,="" arial,="" sans-serif;="" font-size:="" 14px;"="" style="background-color: rgb(255, 255, 255); color: rgb(51, 51, 51);">
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- WriterDr. Da Hye Won and Dr. Ung Lee
- 작성일2021.12.08
- Views661